The field covers a multifunction warming device for perioperative use constituted of a clinical garment with at least one convective apparatus supported on the inside of the garment. More specifically, the field covers attaching a multifunction warming device to a person.
In this specification, use of the term “convective” to denote the transfer of heat from a device to a body refers to the device's principal mode of heat transfer, it being understood that heat may at the same time be transferred from the device to the body by conduction and radiation, although not to the degree of convection.
Convective devices that transfer heat to a human body are known. For example, there are devices that receive a stream of pressurized, warmed air, inflate in response to the pressurized air, distribute the warmed air within a pneumatic structure, and emit the warmed air onto a body to accomplish such objectives as increasing comfort, reducing shivering, and treating or preventing hypothermia. These devices are typically called “convective thermal blankets” or “covers”; for convenience, in this discussion and the following specification, they shall be called, simply, “thermal blankets.” Arizant Healthcare Inc., the assignee of this application, makes and sells such devices under the BAIR HUGGER® brand. One such device is the Model 522 Upper Body Blanket.
Thermal blankets have been specifically designed for particular deployments where therapeutic warming is indicated. Three representative thermal blankets known in the prior art are shown in FIGS. 1A-1D. A “full body” thermal blanket 10 is shown in FIG. 1A. The full body thermal blanket is adapted to lie upon a person and to extend longitudinally along the body of the person in order to cover substantially the person's entire body, from near the ankles or feet up to the neck. A “lower body” thermal blanket 12 is shown in FIG. 1B. The lower body thermal blanket 12 is adapted to lie upon the person and to extend longitudinally along the body of a person in order to cover the person's lower body, from near the ankles or feet up to the waist or pelvis of the person. An “upper body” thermal blanket 15 is illustrated in FIGS. 1C and 1D. The upper body thermal blanket 15 has a bow-tie shape that is adapted to lie upon and extend transversely across the upper body of a person in order to cover the person's chest and extended arms. A head drape 16 may be formed on or attached to the upper body thermal blanket 15 for draping over the head 17 of a person in order to retain warmed air expelled through the blanket 15 about the head to aid in therapeutic warming during surgery. When fed a stream of warmed pressurized air, each of the thermal blankets 10, 12, 15 inflates and distributes the air within itself. While the thermal blanket lies on the person, the warmed pressurized air flows through apertures or interstices in a permeable surface of the thermal blanket which faces the person. These thermal blankets may have one, two, or more inlet ports 18 through which an air hose 19 provides warmed pressurized air from a heater/blower unit (not shown in these drawings).
The construction of prior art thermal blankets is well understood. Examples of specific constructions are given in U.S. Pat. No. 5,620,482, U.S. Pat. No. 5,443,488, U.S. Pat. No. 5,360,439, and U.S. Pat. No. 5,304,213. See also U.S. Pat. No. 5,974,605.
A recent invention disclosed in the referenced Publication No. WO 2003/086500 is directed to a warming device constituted of a clinical garment, such as a robe or gown, and a convective device, such as a thermal blanket, supported on an inside surface of the garment in order to warm a person wearing the garment for comfort. Other inventions described in the publications of other related patent applications identified above expand the functions of the warming device, so that it not only covers a patient after disrobing, but also warms the patient perioperatively for purposes of comfort and/or therapy.
The term “perioperative” is defined in the PDR Medical Dictionary, Second Edition, (Medical Economics Company, 2000), as “around the time of operation.” The perioperative period is characterized by a sequence including the time preceding an operation when a patient is being prepared for surgery (“the preoperative period”), followed by the time spent in surgery (“The intraoperative period”), and by the time following an operation when the patient is closely monitored for complications while recovering from the effects of anesthesia (“the postoperative period”).
Therapeutic warming may be indicated during any one or more of the perioperative periods. For example, for a short operation in a surgery with no warming equipment available, a person may be warmed preoperatively in a preparation area to raise mean body temperature to a level higher than normal in order to store enough thermal energy to maintain normothermia, without heating, intraoperatively. Convective warming therapy is frequently indicated during surgery in order to maintain core temperature. After surgery, it may be necessary to apply therapeutic warming in a recovery area to raise the core temperature to normothermia and maintain it there for a period of time while anesthesia wears off. Alternatively, for a long surgery in an arena with heating equipment available, a person may be warmed for comfort before surgery and warmed therapeutically during and after surgery.
Prior to the invention of the warming devices described in the related applications, therapeutic warming was typically provided by single-function devices such as the thermal blankets shown in FIGS. 1A-1D. An example of use of a full body thermal blanket for therapeutic warming is found in U.S. Pat. No. 6,524,332, “System and Method for Warming a Person to Prevent or Treat Hypothermia”, commonly owned with this application.
With the invention of multifunction warming devices capable of clothing a patient and convectively warming the patient perioperatively, provision may have to be made to manage their position when operated to warm a patient. For example, the activated convective elements of the warming devices or the warming devices themselves may have to be anchored or otherwise secured at a specific location with respect to a patient in order to keep a surgical area clear or to maintain a delivery of convective warming aimed at a specified body portion. Currently, there is no provision in the construction of the warming devices themselves for securing a warming device or a convective element of the warming device with respect to a person.